Feasibility study into use of elemental impurities of sulfamide for use in characterizing different vendors by inductively coupled plasma/mass spectrometry

Inductively coupled plasma-mass spectrometery (ICP-MS) was used to quantitate elemental impurities in sulfamide from seven common vendors, Acros, Aldrich, Alfa-Aesar, Fluka (Lot #1 and Lot #2), Maybridge, Pfaltz and Bauer, and Spectrum (Lot #1 and Lot #2) with the goal of using these impurities to differentiate the sulfamide samples and link the sulfamide back to its vendor. This attribution of the sulfamide back to its vendor is forensically relevant since sulfamide is a precursor to the deadly neurotoxin, tetramethylenedisulfotetramine (TETS). Solution ICP mass spectra identified statistically different concentrations of Cu, Fe, Ni, and Zn among some of the vendors and even in the same lots of the same vendor. These elemental concentrations were entered into discriminant functions which resulted in successful discrimination among the vendors. The two lots of Spectrum were also differentiated while one lot of Fluka was misclassified as the other Fluka lot. These preliminary results indicate the feasibility of using inorganic impurities to cluster vendors with the potential for association or disassociation of an unknown back to a vendor.